Grapefruit knife



FIG. 1 is a perspective view of a grapefruit knife showing our new design;

FIG. 2 is a top plan view of the FIG. 1 grapefruit knife;

FIG. 3 is a left side elevational view of the FIG. 1 grapefruit knife;

FIG. 4 is a right side elevational view of the FIG. 1 grapefruit knife;

FIG. 5 is a bottom plan view of the FIG. 1 grapefruit knife;

FIG. 6 is a back side elevational view of the FIG. 1 grapefruit knife; and,

FIG. 7 is a front side elevational view of the FIG. 1 grapefruit knife. 

The ornamental design for a grapefruit knife, as shown and described. 